Okay, we are tasked with adding 8394 and 5764. Let's begin!

Step 1: We'll start by adding the digits 4 & 4 in column 1 and get 8.

Step 2: We'll start by adding the digits 9 & 6 in column 2 and get 15.
We'll write down the last digit 5 and carry the 1 to the next column.

Step 3: We'll start by adding the digits 3 & 7 in column 3 and get 11.
We'll write down the last digit 1 and carry the 1 to the next column.

Step 4: We'll start by adding the digits 8 & 5 in column 4 and get 14.
We'll write down the last digit 4 and carry the 1 to the next column.

So, 8394 + 5764 = 14158.

